The following relates generally to wireless communication, and more specifically to a downlink control channel structure for low latency applications.
Wireless communications systems are widely deployed to provide various types of communication content such as voice, video, packet data, messaging, broadcast, and so on. These systems may be capable of supporting communication with multiple users by sharing the available system resources (e.g., time, frequency, and power). Examples of such multiple-access systems include code division multiple access (CDMA) systems, time division multiple access (TDMA) systems, frequency division multiple access (FDMA) systems, and orthogonal frequency division multiple access (OFDMA) systems, (e.g., a Long Term Evolution (LTE) system). A wireless multiple-access communications system may include a number of base stations, each simultaneously supporting communication for multiple communication devices, which may be known as user equipments (UEs).
Wireless multiple-access technologies have been adopted in various telecommunication standards to provide a common protocol that enables different wireless devices to communicate on a municipal, national, regional, and even global level. LTE is an example of a telecommunication standard. LTE is designed to improve spectral efficiency, lower costs, improve services, make use of new spectrum, and better integrate with other open standards. LTE may use OFDMA on the downlink (DL), single-carrier frequency division multiple access (SC-FDMA) on the uplink (UL), and multiple-input multiple-output (MIMO) antenna technology.
A base station may transmit to one or more UEs using a transmission time interval (TTI) that is reduced in length. Such a TTI may be referred to as a shortened TTI (sTTI) and a user receiving a sTTI may be a low latency user. A sTTI may be divided into a number of resource blocks across a system bandwidth, and each of the resource blocks may be allocated to a UE by a base station. The base station may transmit control information or a control message in a first portion of the resource block to provide the resource allocations. A low latency user may attempt to decode the control information in the resource block. As sTTIs become shorter, it is ever more important to reduce the control overhead. Thus, it is desirable to efficiently communicate control information, and minimize the amount of processing time required for a UE to receive and decode the control information.